Centuries before the establishment of modern neuroscience, master painters sought to create works that gave viewers an intense experience, summoning emotions or even activating other senses. Today, the neurological mechanisms underlying these responses are the subject of fascination to artists, curators and scientists alike.

At a pair of related AAAS events, experts described new insights into how engaging with art — either as an observer or creator — affects the brain.

"The Arts and the Brain: What Does Your Brain See? What Does Your Brain Hear?," the fourth and final event in the 2013 Neuroscience and Society speaker series sponsored by the AAAS Scientific Responsibility, Human Rights and Law Program and the Dana Foundation, took place 24 October in the AAAS Auditorium.

On the same day, a new exhibit called "Beauty and the Brain Revealed" opened in the AAAS Art Gallery. The exhibit was inspired by a show Gary Vikan curated as director of the Walters Art Museum in Baltimore.

Six years ago, Vikan, a self-described "neuroscience junkie," met Ed Connor, director of the Zanvyl Krieger Mind/Brain Institute at Johns Hopkins University, who was studying monkeys' responses to aesthetic stimuli. When Connor said that he planned to study humans' responses to similar stimuli, "it occurred to me that we could do that in a museum," Vikan said.

At the exhibit, which runs through 3 January 2014, attendees wear 3D glasses, look at posters covered with abstract shapes, and identify which shapes they find the most — and least — appealing. They then have the opportunity to compare their results to those of human subjects studied in the lab and with fMRI imaging, as well as those of the thousands of attendees who visited the exhibit in 2010 when it was hosted by the Walters Art Museum.

"Once you circle these little things and come to the end of this little project, you'll be invited to compare where you came out against what the results of this experiment were and are," Vikan said. "What you'll find in this show is that there is an amazing convergence. The people that came to the museum liked and disliked the same categories of shapes as the people in the lab as the people in the fMRIs."

"Art accesses some of the most advanced processes of human intuitive analysis and expressivity and a key form of aesthetic appreciation is through embodied cognition, the ability to project oneself as an agent in the depicted scene," said Christopher Tyler, director of the Smith-Kettlewell Brain Imaging Center, during the related panel discussion.

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Learn more about "Beauty and the Brain Revealed," now showing in the AAAS Art Gallery

Watch a video of the public discussion "The Arts and the Brain: What Does Your Brain See? What Does Your Brain Hear?"

Embodied cognition is "the sense of drawing you in and making you really feel the quality of the paintings," Tyler explained. For example, viewers appreciate Botticelli's painting "The Birth of Venus" because it makes them feel as though they are floating in with Venus on the seashell. Similarly, viewers can feel the flinging of the paint on the canvas when appreciating a drip painting by Jackson Pollock.

Mirror neurons, cells in the brain that respond similarly when observing and performing an action, are responsible for embodied cognition. "Performing an action requires the information to flow out from the control centers to the limbs," Tyler said. "But observing the action requires the information to flow inward from the image you're seeing into the control centers. So that bidirectional flow is what's captured in this concept of mirror neurons and it gives the extra vividness to this aesthetics of art appreciation."

Artists are known to be better observers and exhibit better memory than non-artists. In an effort to see what happens in the brain when an individual is drawing and whether drawing can increase the brain's plasticity, Tyler's colleague Dr. Lora Likova, a scientist at Smith-Kettlewell, developed a way to capture an individual's drawing during an fMRI scan so that she could study it in congenitally blind individuals. Subjects explored raised-line tactile images with their fingers and spent a week learning to draw from memory alone, Tyler explained.

While congenitally blind people usually don't have activation in the visual area of the brain, in brain scans done after the subjects were taught to draw from memory, "Likova found that the training procedure produced dramatic enhancement of the activation, very specific to the primary visual cortex or what would have been the primary visual cortex in these congenitally blind subjects," Tyler said. "So that's a remarkable form of rapid neural plasticity induced by this unique training procedure."

Nina Kraus, the Hugh Knowles Professor of Communication Sciences, Neurobiology & Physiology, and Otolaryngology at Northwestern University as well as the principal investigator at the Auditory Neuroscience Laboratory, found that playing music also affects the brain. "We have found, and others have found, that musicians have stronger auditory and listening cognitive skills across the lifespan," she said.

Hearing speech in noise is one area in which musicians are uniquely skilled. In standardized tests, musicians across the lifespan were much better than the general public at listening to sentences and repeating them back as the level of background noise increased, Kraus said. "Interestingly, even if you are an older musician and you had hearing loss, your ability to hear in noise is still better than an older person's ability to hear in noise if they have normal hearing," she said.

Most research on the effects of music education has been done on populations that are privileged enough to afford private music instruction so Kraus is studying music instruction in group settings, one in Chicago public schools and another in the Harmony Project in Los Angeles, both in low income areas, to see if those students received similar benefits despite their low socioeconomic status.

Kraus assessed the biological impact of poverty indexed by maternal education. "We found that adolescents with mothers who had less education had more neural noise in the absence of sensory stimulation than kids whose mothers had spent more time in school," Kraus said. "They had more background noise, like static on your radio. And they responded to the signal less. So that's a catastrophic signal-to-noise situation. Moreover, they had less consistent responses to sound."

"We are seeing that kids from lower socioeconomic backgrounds, as measured by maternal education, have an inefficient auditory system that is noisier and poorer at responding to sound," Kraus said. "We are also seeing that after two years of training — one year was not enough — the brains of the kids who are in music have changed so that they are now less impacted by noise. Biologically, their nervous systems have become more efficient machines and this has positive consequences for both reading skills and hearing in noise."

Musicians are also known for their ability to keep rhythm, a skill that is correlated with reading ability and how precisely the brain responds to sound. After one year, students who participated in the group music instruction were faster and more accurate at keeping a beat than students in the control group, Kraus said.

"To sum things up, we are what we do and our past shapes our present," Kraus said. "Auditory biology is not frozen in time. It's a moving target. And music education really does seem to enhance communication by strengthening language skills."

"When you're doing art, your brain is running full speed," Vikan said. "It's hitting on all eight cylinders. So if you can figure out what's happening to the brain on art, you know a whole lot about the brain."